Interplay of brain structure and function in neonatal congenital heart disease

Objective: To evaluate whether structural and microstructural brain abnormalities in neonates with congenital heart disease (CHD) correlate with neuronal network dysfunction measured by analysis of EEG connectivity. Methods: We studied a prospective cohort of 20 neonates with CHD who underwent continuous EEG monitoring before surgery to assess functional brain maturation and network connectivity, structural magnetic resonance imaging (MRI) to determine the presence of brain injury and structural brain development, and diffusion tensor MRI to assess brain microstructural development. Results: Neonates with MRI brain injury and delayed structural and microstructural brain development demonstrated significantly stronger high-frequency (beta and gamma frequency band) connectivity. Furthermore, neonates with delayed microstructural brain development demonstrated significantly weaker low-frequency (delta, theta, alpha frequency band) connectivity. Neonates with brain injury also displayed delayed functional maturation of EEG background activity, characterized by greater background discontinuity. Interpretation: These data provide new evidence that early structural and microstructural developmental brain abnormalities can have immediate functional consequences that manifest as characteristic alterations of neuronal network connectivity. Such early perturbations of developing neuronal networks, if sustained, may be responsible for the persistent neurocognitive impairment prevalent in adolescent survivors of CHD. These foundational insights into the complex interplay between evolving brain structure and function may have relevance for a wide spectrum of neurological disorders manifesting early developmental brain injury

The limits of Web–based empowerment: Integrated water resource management case studies

This article is an analysis of the limits of Web–based empowerment of the voiceless, leveraging from five Integrated Water Resource Management (IWRM) case studies, and motivated by several recent Web–based empowerment success stories. For IWRM, the Web picture is of an emerging academic–trained professional community of water professionals, with close ties to national governments, but closer ties to powerful international NGOs and NGOs sponsored by western governments. Nevertheless, no Web evidence was found for the involvement of ordinary citizens in IWRM, despite this being a key theoretical goal, and no Web evidence was found of the emergence of genuine grass–roots pressure groups. A comparison with other high–profile Web–enabled issues, such as the anti–World Trade Organisation protests, indicates that the Internet can be used to help give a voice to the voiceless in many different ways, but that its use at a grassroots level is not automatic

Web issue analysis: an integrated water resource management case study

Metadata onlyIn this article Web issue analysis is introduced as a new technique to investigate an issue as reflected on the Web. The issue chosen, integrated water resource management (IWRM), is a United Nations-initiated paradigm for managing water resources in an international context, particularly in developing nations. As with many international governmental initiatives, there is a considerable body of online information about it: 41,381 hypertext markup language (HTML) pages and 28,735 PDF documents mentioning the issue were downloaded. A page uniform resource locator (URL) and link analysis revealed the international and sectoral spread of IWRM. A noun and noun phrase occurrence analysis was used to identify the issues most commonly discussed, revealing some unexpected topics such as private sector and economic growth. Although the complexity of the methods required to produce meaningful statistics from the data is disadvantageous to easy interpretation, it was still possible to produce data that could be subject to a reasonably intuitive interpretation. Hence Web issue analysis is claimed to be a useful new technique for information science

Prevalence, Risk Factors, and Impact of Preoperative Seizures in Neonates With Congenital Heart Disease

Purpose: The purpose of this study was to assess the prevalence, risk factors, and impact of electrographic seizures in neonates with complex congenital heart disease before cardiac surgery.Methods: A cohort of 31 neonates with congenital heart disease monitored preoperatively with continuous video-EEG (cEEG) was first reviewed for electrographic seizure burden and EEG background abnormalities. Second, cEEG findings were correlated with brain MRI and 18-month outcomes.Results: Continuous video-EEG was recorded preoperatively for a median duration of 20.5 hours (range, 2.5–93.5 hours). The five neonates (16%; 95% confidence interval, 5.5% to 34%) with seizures detected on cEEG in the preoperative period had a diagnosis of transposition of the great arteries or similar physiology, detected in four of five postnatally. None of the 157 recorded electrographic seizures had a clinical correlate. The median time to first seizure was 65 minutes (range, 6–300 minutes) after cEEG hookup. The median maximum hourly seizure burden was 12.4 minutes (range, 7–23 minutes). Before the first electrographic seizure, a prolonged interburst interval (>10 seconds) was not associated with seizures (coefficient 1.2; 95% confidence interval, −1.1 to 3.6). MRI brain lesions were three times more common in neonates with seizures. Sharp wave transients on cEEG were associated with delayed opercular development.Conclusions: In this cohort, preoperative electrographic seizures were common, were all subclinical, and were associated with MRI brain injury and postnatal diagnosis of transposition of the great arteries. The findings motivate further study of the mechanisms of preoperative brain injury, particularly among neonates with a postnatal diagnosis of transposition of the great arteries.</p

Declining Incidence of Postoperative Neonatal Brain Injury in Congenital Heart&nbsp;Disease

BackgroundBrain injury is common in neonates with complex neonatal congenital heart disease (CHD) and affects neurodevelopmental outcomes.ObjectivesGiven advancements in perioperative care, we sought to determine if the rate of preoperative and postoperative brain injury detected by using brain magnetic resonance imaging (MRI) and associated clinical risk factors have changed over time in complex CHD.MethodsA total of 270 term newborns with complex CHD were prospectively enrolled for preoperative and postoperative brain MRIs between 2001 and 2021 with a total of 466 MRI scans. Brain injuries in the form of white matter injury (WMI) or focal stroke and clinical factors were compared across 4 epochs of 5-year intervals with logistic regression.ResultsRates of preoperative WMI and stroke did not change over time. After adjusting for timing of the postoperative MRI, site, and cardiac group, the odds of newly acquired postoperative WMI were significantly lower in Epoch 4 compared with Epoch 1 (OR: 0.29; 95%&nbsp;CI: 0.09-1.00; P&nbsp;=&nbsp;0.05). The adjusted probability of postoperative WMI declined significantly by 18.7% from Epoch 1 (24%) to Epoch 4 (6%). Among clinical risk factors, lowest systolic, mean, and diastolic blood pressures in the first 24 hours after surgery were significantly higher in the most recent epoch.ConclusionsThe prevalence of postoperative WMI has declined, whereas preoperative WMI rates remain constant. More robust postoperative blood pressures may explain these findings by minimizing periods of ischemia and supporting cerebral perfusion. These results suggest potential modifiable clinical targets in the postoperative time period to minimize the burden of WMI